When a woman (or feminine man) girates there gluteus maximus in such a way that resembles a person having a seizure standing upright. At first glance it seems to be a prettysexy dance move, but upon closer inspection the individual looks quite uncomfortable like they're vigorously shaking an extremely clingy shitlock off of of they assbeard.

A: Hey Secretia. Check out that crazy bootch havin a fit on the dance flo.
B: Damn Laqueefa! That bitch might really be sick or some shit.
A: Nah, she just be havin a massive booty seizure!

C: Michaella are you up for a brief jaunt down to the local disco, I feel a booty seizure coming on.
D: Why yes Bruce, but you must not forget to bring your dance helmet in case you go full on seize and land flat on your perfect little Shnoz.
C:(Poot)